Catalyst for the production of ethylene glycols and ethylene hydrocarbons



Patented Mar. 25, 1930 UNITED STATES PATENT OFFICE ALEXANDER T. maxmorr,OF'NEW YORK, N. Y., ASSIGNOB TO THE NA'UGATUCZ CHEMICAL COMPANY, OFNAUGATUCK, CONNECTICUT, A COBPOMTION' 01' CON- NECTICUT CATALYST FOR THEPRODUCTION OF ETHYLENE GLYCOLS AND Mmm muo- CABBONB Io Drawing.

The present invention relates to the production of homologues ofethylene glycol and ethylene hydrocarbons, and to the production ofpinacol from acetone. More particu- 6 larly the invention relates to theactivation of an aluminum reagent by the formation of a thin layer of anactive amalgam upon the surface of the aluminum.

The ordinary method of amalgamating 10 aluminum for use in the reductionof organic compounds does not impart to it sufficient activity.According to the present invention the introduction of a third metaluntothe amalgam greatly .increases the activity thereof and at the same timepermits carrying out reactions which are impossible with aluminumactivated b the usual methods. The metal introduce into the ordinaryaluminum-mercury amalgam is preferably zinc. Other metals, such ascadmium etc. may also be employed. While the invention is not limited toany particular method of forming the reagent, the following may serve asillustrations. The amalgamation may be conducted by the use of solublesalts of mercury and of the third metal, these saltsbe ng precipitatedupon aluminum which is 1mmersed or suspended in the solution of thesesalts. Another method of forming the amalgam of this invention is tomelt the aluminum and third metal together thus forming an alloy whichmay then be ground to any desired degree and subsequently amalgamated onits surface by treatment with the mercury salts. When acetone and otherketones and derivatives thereof are treated with the improved reagent itwill be found that the nature of the reaction is dependent upon theamount of third metal present in the amalgam. When ketones are treatedwith aluminum, upon which is deposited an aluminummercury-zinc amalgamcontaining 1 to 2% of zinc, a direct addition of aluminum to the ketoneoccurs, with the formation of Application filed Kay 18, 1828. Serial Io.109,961.

aluminum lycolates according to the followmg genera reaction:

If the glycolate thus obtained be treated with water, a glycol andaluminum hydroxide are obtained:

Y Yam When acetone is treated with the improved reagent the end productwill be tetramethyl ethylene glycol or pinacol.

If the amount of third metal be increased to 7 30% by weight of thealuminum, ethy lene hydrocarbons are produced when ketones are treated.For example acetone will yield propylene:

The above equations describe reactions which take place in a non-aqueousmedium. If water be introduced into the reacting mixture, nascenthydrogen is evolved. This nascent hydrogen will lead to the formation ofa series of reduction products. Under such conditions ketones willproduce secondary alcohols:

(311 60.611, 2H= CH,.GH.OH.CHa

tacky material is formed in which, the zinc may act as a cementingsubstance to keep the aluminum and mercury together. By 1ncreasing thepercentage of zinc, say up to 30% in the aluminum zinc alloy, a largepercentage of propylene will appear in the reaction when acetone is usedas the starting material. When an alloy contains 7% of zinc, propylenecontinues to appear in large quantities in this reaction. When theamount of zinc is reduced to 2% or less, very l1ttle propylene willappear, and pinacol is obtained as the main product.

The same results may be obtained by using mixtures of zinc and mercuricsalts with aluminum in the preparation of the amalgam.

For instance if amalgamation of the aluminum is carried out by using asolution of 5% of zinc chloride and 10% mercuric chlo ride, thetreatment of acetone with such amalgamated aluminum yields pinacol inlarge quantities, and relatively free from propylene and other products.

The advantage gained by the present invention is that any kind ofaluminum may be employed, and the aluminum may be used in the form offilings or even in the form of rough shavings. Moreover it has been theexperience of organic chemists that not all makes of pure aluminum maybe employed in carrying out these catalytic reactions. Indeed it is thegeneral experience that there is but one kind of aluminum a product madein Germany which will yield pinacol as the product of the reduction ofacetone. By'practicing the present invention, however, any kind ofaluminum may be employed and even better results obtained than with theabovementioned foreign product. The percentage of zinc present in thealloy may be varied within wide limits, depending upon the productdesired. For the production of pinacol approximately 3% or less of zincwill give excellent results. If propylene or other ethylene hydrocarbonsare desired, a higher amount of zinc, even up to 30%, may be used toadvantage, although quantities of the unsaturated hydrocarbon will beobtained. with 7% of zinc. It is understood, of course, that thepercentage of zinc is figured as metallic zinc. If a zinc compound isemployed, cal culations are made accordingly. For example zinc chloridewill analyze'a little less than 50% of zinc as metal. It will thus beseen that the reduction of organic oxygencontaining substancesparticularly the ketones and other compounds which are ordinarilyreduced by nascent hydrogen formed y amalgamated aluminum in thepresence of water, can be carried out much more eco nomically and withbetter results than has hitherto been possible. Furthermore theinvention possesses the advantage that any type of aluminum can beemployed and that it is not essential to have the aluminum in a verywhich the improved aluminum amalgam may be put. It will be understood,however, that the reagent may be variously employed in reductionreactions in the presence of water, as

wellas in reactions where the aluminum forms a compound with all or partof the reacting material. The claims are therefore to be interpretedbroadly. The expressions metallic element, metal and zinc as used in theclaims, are descriptive of these mate- 7 rials as single elements, butthe terms include also compounds of the elements, and the percentagesgiven in the claims refer to percent ages of the metal, not of its salt.It is to be understood therefore that salts of zinc and the other metalswhich may be employed are comprehended by the claims.

Having thus described my invention, what I claim and desire to protectby Letters Patent is: I

1. An improved reagent for the treatment of organic compounds, namely,an amalgam consisting solely of mercury, aluminum and a metal of thegroup consisting of zinc and cadmium.

2. An improved reagent for the treatment of organic compounds, namely,an amalgam consisting solely of mercury, aluminum and zinc.

Signed at New York, New York, this 4th day of May, 1926.

ALEXANDER T. MAXIMOFF.

CERTIFICATE OF CORRECTION.

Patent No. 1,752,016. Granted March 25, 1930, to

ALEXANDER T. MAXIMOFF.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 1,line 54, in the first formula for R' R" second occurrence read R' R; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the case in the PatentOffice.

Signed and sealed this 29th day of April, A. D. 1930.

M. J. Moore, (Seal) Acting Commissioner of Patents.

